C-17 missile countermeasures laser turret

Directional Infrared Counter Measures (DIRCM) are a class of anti-missile systems produced to protect

aircraft An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

from

infrared homing Infrared homing is a Missile guidance#Passive homing, passive weapon guidance system which uses the infrared (IR) light emission from a target to track and follow it seamlessly. Missiles which use infrared seeking are often referred to as "he ...

missiles, primarily MANPADS and similar simple systems. Earlier

infrared countermeasures An infrared countermeasure (IRCM) is a device designed to protect aircraft from infrared homing ("heat seeking") missiles by confusing the missiles' infrared guidance system so that they miss their target (electronic countermeasure). Heat-see ...

flare A flare, also sometimes called a fusée, fusee, or bengala, bengalo in several European countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illuminatio ...

s or hot block systems that produce random flashes of IR light are semi- or omnidirectional. This results in the missile seeker receiving relatively little IR energy due to the

inverse square law In science, an inverse-square law is any scientific law stating that the observed "intensity" of a specified physical quantity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental cau ...

. DIRCM systems instead aim their IR output directly at the missile using some source of tracking information and a trainable emitter. This allows a relatively small device to overwhelm the missile seeker by focusing all of its output on it. Examples are produced by many aerospace companies, such as Aselsan, Leonardo S.p.A.,

Elbit Systems Elbit Systems Ltd. is an Israel-based international military technology company and defense contractor. Founded in 1966 by Elron, Elbit Systems is the primary provider of the Israeli military's land-based equipment and unmanned aerial v ...

Northrop Grumman Northrop Grumman Corporation is an American multinational Aerospace manufacturer, aerospace and Arms industry, defense company. With 97,000 employees and an annual revenue in excess of $40 billion, it is one of the world's largest Arms industry ...

ITT Corporation ITT Inc., formerly ITT Corporation, is an American worldwide manufacturing company based in Stamford, Connecticut. The company produces specialty components for the aerospace, transportation, energy and industrial markets. ITT's three businesses ...

, and

BAE Systems BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...

. A Russian example is the 101KS-O.

Method of operation

The systems use an effective method of jamming infrared missile seekers through the sensor aperture and can be placed in either active or standby mode. In the standby mode, the

aircrew Aircrew are personnel who operate an aircraft while in flight. The composition of a flight's crew depends on the type of aircraft, plus the flight's duration and purpose. Commercial aviation Flight deck positions In commercial aviatio ...

must select the active mode to begin jamming

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

(IR) threats. The pulsing flashes of IR energy confuse the missile guidance system, preventing the tracking of the target aircraft.

Systems

AN/AAQ-24

The AN/AAQ-24 system is a directional infrared countermeasure (DIRCM) system. It consists of a missile warning system ( AN/AAR-54), an integration unit, a processor, and laser turrets (Small Laser Transmitter Assembly, SLTA). Early versions of this system used an

arc lamp An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, ...

to generate the jammer

signal A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology. In ...

. The newer versions of this system manufactured by

use diode-based

laser pumping Laser pumping is the act of energy transfer from an external source into the gain medium of a laser. The energy is absorbed in the medium, producing excited states in its atoms. When for a period of time the number of particles in one excited stat ...

systems known by the name GUARDIAN. These systems are intended for potential fitting to commercial carriers pending the completion of multiple tests on the viability of such options. The AN/AAQ-24 system is installed in the Northrop Grumman Guardian system marketed for commercial aircraft. The system will be installed by 2025 on

C-17 Globemaster III The McDonnell Douglas/Boeing C-17 Globemaster III is a large military transport aircraft developed for the United States Air Force (USAF) between the 1980s to the early 1990s by McDonnell Douglas. The C-17 carries forward the name of two previ ...

, MC-130, CV-22 Osprey, and the CH-53E Super Stallion. In 2010, the US Defense Security Cooperation Agency announced to

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...

a possible sale to Canada of eight AN/AAQ-24(V) DIRCMs including equipment and services for a total value of up to US$72 million. Other material and services would include publications and technical documentation, personnel training and training equipment, U.S. Government (USG) and contractor engineering, technical and logistics support services. Large Aircraft Infrared Counter-Measure system (LAIRCM) was a

US Military The United States Armed Forces are the military forces of the United States. U.S. federal law names six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and the Coast Guard. Since 1949, all of the armed forces, except th ...

requirement for protecting its large aircraft from infrared-guided missiles. The AN/AAQ-24 Nemesis system was produced to serve this requirement. LAIRCM-Lite is a C-17 program that uses a combination of laser jamming DIRCM and flares due to the limited availability of LAIRCM components.

101KS-O

The 101KS-O is a DIRCM system mounted on the Sukhoi Su-57 fighter jet. It has sensors that are placed in turrets, which are mounted on two points: the dorsal spine and the forward fuselage under the cockpit. It uses

modulated Signal modulation is the process of varying one or more properties of a periodic waveform in electronics and telecommunication for the purpose of transmitting information. The process encodes information in form of the modulation or message ...

laser-based countermeasures to confuse or destroy incoming missiles' tracking mechanisms. The 101KS-O is the first DIRCM that is deployed on any fighter aircraft.

References

External links